int predictRating(Film f, User u) {
        int res = 4;
        if (f == null && u != null) {
            res = (int) Math.round(u.avarageRating);
        } else {
            if (f != null && u == null) {
                res = (int) Math.round(f.avarageRating);
            } else {
                if (f != null && u != null) {
                    res = (int) Math.round(Math.sqrt(f.avarageRating
                            * u.avarageRating) - 0.1);
                }
            }
        }
        if (res < 1)
            res = 1;
        if (res > 5)
            res = 5;
        return res;
    }